Image forming apparatuses are apparatuses that form an image on tangible print medium, e.g., paper, according to an input image signal, and may be, for example, a printer, a copier, a fax machine and a so-called multi-functional peripheral that combines some of the functionalities of the afore-mentioned.
An image forming apparatus generally includes a main body that defines the external appearance of the image forming apparatus and various components supported or accommodated in the main body. Such components may include, for example, a print media supply unit for storing print media, a developing unit for forming an image of developer on a print medium supplied by the print media supply unit, a fusing unit for fixing the developer on the print medium and an exit unit for discharging the print medium, on which the developer image is fixed, outside the main body.
By way of an example, in an image forming apparatus of the above described configuration, a light modulated with image information is irradiated on a photoconductor (often also referred to as “an image carrier” or a “photosensitive member”), the surface of which had been pre-charged to a uniform electrical potential, so as to form an electrostatic latent image on the surface of the photoconductor based on the potential difference resulting from the light exposure. So created electrostatic latent image is then developed into a visible image by applying developer that adhere to selective portions of the surface of the photoconductor due to the potential differences defined by the electrostatic latent image. The visible image of developer is then transferred from the photoconductor onto a print medium supplied from the print media storage unit. The visible image so transferred to the print media is fused or permanently fixed to the print medium using a fusing unit to thereby complete the image formation. After the completion of the image formation, the print medium bearing the fixed developer image is discharged from the main body by an exit unit.
A developing unit of such an image forming apparatus typically includes one or more processing members operable to accomplish the above described formation of a visible image. Examples of such processing members may include, a photoconductor for supporting thereon an electrostatic latent image, a developing body for supplying the developer to the photoconductor so as to form a visible image, a developer storage part to store the developer, a waste developer storage part to store the waste developer that remain residual after a development of an electrostatic latent image, a cleaning unit to clean the waste developer remaining on the photoconductor and a charging unit to charge the surface of the photoconductor to a potential level.
In a developing unit, one or more of the afore-mentioned processing members are supported, in some cases, rotatably, in the frame that defines the external appearance of the developing unit. The frame of the developing unit may include a number of sub-frames. When the sub-frames are not assembled precisely, the positions of the processing members supported by the sub-frames may not be properly aligned, thus possibly resulting in defects in the images. The misalignment of the processing members may also result in the excessive wearing of the processing members due to unintended contacts and/or friction between the processing members, and may even cause the leakage of the developer stored in the developing unit. Assembly of a developing unit may involve steps to ensure sufficient level of precision. Thus, a developing unit capable of being assembled with simpler assembly process is thus desirable.